1. Field
This patent document relates to a semiconductor system and a method for testing a semiconductor device.
2. Description of the Related Art
Semiconductor devices including DRAM and the like have been changed in various manners to satisfy a variety of demands. One such structural change is the development of a multi-chip package (MCP). A MCP is a packaged chip containing multiple chips. The packaging technology for semiconductor devices has continuously developed to reduce size and increase storage capacity. Recently, various stacked semiconductor package technologies have developed that are efficient to mount as well as able to reduce size and increase storage capacity.
When a semiconductor package is fabricated, a probe test device is used to perform an OS (Open/Short) test to detect whether input/output pins (for inputting/outputting signals to/from a semiconductor device included in the semiconductor package) are properly coupled to the internal circuitry. Furthermore, when a defective cell is detected after the packaged function test device tests whether the semiconductor device operates properly, the defective cell is repaired with a redundancy cell. The OS test detects whether the input/output pins of the semiconductor device in the semiconductor package is properly coupled to balls of the semiconductor package. This test also determines whether signals inputted to the semiconductor package can be properly transmitted to the semiconductor device, or whether signals transmitted from the semiconductor device can be properly output from the semiconductor package.
The OS test is performed before the package test because the function test result can only be trusted only when there are no defects in the OS test. That is, defective cells can be detected and repaired under the assumption that the input/output pins are properly coupled. In this way, semiconductor devices that would otherwise have to be discarded can be saved.
However, in order to reduce fabrication time and costs, an OS test using a probe test device may be skipped, and a package function test device may be used directly to perform a function test and a repair operation. In this case, it is impossible to guarantee that there is no OS defect in the input/output pins of the semiconductor device.